Process of making colored sand.



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.roHu oo'rrnn PELTON, or snn rnancrsco, oatrronnra.

; rnocnss or MAKING COLORED SAND.

mam. 1N0 Drajiving.

To all whom it may concern:

Be. it known that I, J OHN Coma PEL'roN,

a citizen of the United States, residing at San Francisco, in the county of San Fran cisco and State of California, have invented a new and useful Process of Making Colored Sand, of which the following is a specification.

This invention relates to the. preparation of sand for use in building. construction, for example, as an aggregate or.-ing redient for mortar, cement, plaster, roofing paper, etc., and the primary object of the invention is to provide material of this character which will enable any desired shade of building stone, block, mortar and roofingpaper to e produced without the mixture of extraneous coloring matter. I

Another object of this invention is to provide for permanency and greater uniformity, intensity and brilliancy in the coloring of the sand than is possible with the processes heretofore known.

A further object is to so treat the'grains of sand that the coloring matter will: be,

enabled to penetrate into the interior of said grains to a maximum degree.

A further ob]ect'1s to provide a process.

in which the coloring is fixed in the sand pear hereinafter.

and is not liable to wash out or fade.

Other objects of the invention will ap-' In carrying out my invention, sand to be colored is first treated to widely difierent' degrees of temperature andto efi'ect this the grains of sand are burned or heated red hot and while 'hot are suddenly cooled or given a cold fluid bath. The heat causes the heated sand is suddenly cooled the shock I or sudden change of temperature causes the grains "to contract quickly thus setting up duces to greater adhesion internal stresses and strains so that the grains crack and partly break and become irregular in contour thus' making it more susceptible to penetration by coloring matter and more capable of holding the color. Sand treated in this way is improvedfin quality for cement work and the like, as the jagged or rough nature of the grains conbetween the grains and the cement particles.

The cold bath may also constitute the coloring bath and if the coloring is to be efi'ected in this way a coloring agent or agents Specification of Letters Patent.

i for imparting color to the sand oriinpart- 1ng theappearance of color to the sand is dissolved or suspended in a suitable solvent or medium such as cold water After the preliminary heating the sand maybe thrown The coloring agents which I have suc-' cessfully employed consist ofany suitable coloring-producing metallic salts or' compounds.

The nature of the agent dependsu'pon the A Patented Qua M, ram.

Application filed July 19, 1915. Serial No. 40,654. 5

color which is to be given the sand, and I apply this metallic matterto the'sand'in the form of a solution" while it is dissolved.

or, suspended in a suitable solvent or carrying medium, theYsand being soaked-or. im-

intensity and bri iancy of color are desired" the sand while hot is subjected to ammonia in the gaseous or aqueous' forms to efiect this result. If it is desired to further set or fix the coloring and increase the brilliancy thereof the sand while hot is given a' bath in cold liquid. containing a coloring agent. .This adds coloring to the sand and causes the sand to contract and the'coloring in the crevices to be more pronounced.

In the production of sand having abufi, brown or black color, the coloring matter is a salt or compound of iron and'to produce the same I may proceed as follows: Sulfid of iron (ferrous sulfid) is pulverized and made into a paste with commercial sulfuric acid. The resulting product is dilutedwith water depending upon the shade of color desired, the sand being lighter in pro portion'to the amount of water for the dilution of the solution. 'Sand which has been of 100 C. orhigher if desired, to increase the brilliancy of the coloring. The shade of color produced and the brilliancy thereof depends upon the temperature of'the burning as Well as the amount of coloring matter used. a

It is not'necessary except in cases where a brilliant coloring is desired to heat the sand and subject it to a cold water coloring bath after it has been first heated and then given the initial cold Water coloring bath, since by first heating and then giving the sand a cold Water coloring bath a good coloring will begiven the sand.

The sand made as above described is permanent in color and may be used as an ingredient of mortar, plaster, etc., in the formation of building blocks and the like and in building and plastering walls, and it imparts its characteristic color to the molded or built product, the color being permanent, brilliant and uniform. The sand thuscolored is also of great commercialvalue in the preparation of colored roofing paper, of which the process for making will be disclosed in a separate application.

Byusing metallic salts of different kinds othercolors may be produced; for example, to produce a blue color, a copper salt is used. For this purpose pure copper may be dissolved in nitric acid and the sand is soaked in the resulting solution for several days and then dried. This gives a permanent blue color which is unaffected by moisture or other influences. By subjecting this blue colored sand to the action of ammonia either in'the form of gas or aqueous solution, the

color of, the sand may be changed to green.

The color of this blue sand may be deepened by burning same or heating it to a high i fate of soda, by first soaking the sand in said solution, the rest of the process being the same as hereinbefore described, the sand be ing dried, burned, subjected to ammonia while hot and the coloring the heated sand a cold bath.

Certain chemicals will intensifycertain colors in the sand if the sand is pre-treated with the desired chemical before given the coloring bath; for example, hyposulfate .of

sodawill intensify browns and reds when added to the sand before it is given the coloring bath.-

fixed by givin then burning the sand.

Various colors may be given the sand with the use of different coloring agents in the cold Water bath. For example, when am monia and hyposulfate of soda is added to the water, and sand which has been colored blue is thrown into the water, the sand is changed from blue to purple.

I am aware that certain parts or steps of this process are old, for instance the mere color bath treatment and subsequent burning of the sand, but it is particularly noted that I have discovered several additional steps, most notable of which is the exposure of. the sand to extremes of temperature to change the physical character of the sand so that it is more susceptible to color and so that the color is proof against washing out and fading.

I claim:

1. The process of coloring sand which consists in applying a coloring agent in liquid form to the sand, drying the sand, burning the sand and then giving the sand while hot a cold fluid bath to fix the coloring.

2. The process of coloring sand which consists in applying a liquid coloring agent thereto, drying the sand, burning the sand and then subjecting the heated sand to ammonia.

3. The process of coloring sand which consists in applying a liquid coloring agent thereto, drying the sand, burning the sand, then subjecting the heated sand to ammonia, and then giving the sand a cold fluid bath while heated.

4. The process of coloring sand which consists in heating the sand, and then giving the heated sand a cold water bath in water containing a coloring agent. 5'. The process of coloring sand which consists in soaking the sand in a liquid coloring agent, drying the sand, heating the sand, and then throwing the heated sand into cold water containing a coloring agent whereby the coloring of the sand is changed.

6. The process of making colored sand, which process comprises heating the sand, giving the hot sand a cold color bath, and

In testimony whereof, I have hereunto set my hand at San Francisco, Oallfornia, this 13th day of July, 1915.

Y JOHN COTTER PELTON.

'In presence of- L. BELLE WEAVER,

A. F. Sonmm'reaunn. 

